High assay decabromodiphenylethane, a.k.a. α,ω-bis(pentabromophenyl)ethane, is currently manufactured by the bromination of 1,2-diphenylethane in the presence of a large excess of bromine, using anhydrous aluminum chloride as the catalyst. The main reason for using such a large excess (usually 80%-150% stoichiometric excess) is that bromine not only acts as a reagent but also as a solvent which is required for effective mixing. Excess bromine is then recovered and recycled to the next batch. However, using such a large excess of bromine not only leads to the formation of certain unwanted impurities but also results in substantial amount of free bromine being trapped inside the particles during product formation. This free bromine which is trapped within the product particles, commonly referred to as occluded free bromine, must be removed from the crude product before it can be used as a flame retardant in plastics. It is preferred that decabromodiphenylethane, like all other flame retardants, should have no free bromine left in the particles. In practice, however, there is always some (200-300 ppm) that remains in the finished product. Although trapped bromine can be effectively removed from the particles by using recrystallization from solvents, such processing is commercially impractical for materials like decabromodiphenylethane, which has extremely poor solubility in nearly all organic solvents. For example, solubility of decabromodiphenylethane is about 0.2 wt % in dibromomethane at reflux (98° C.), about 0.9 wt % in refluxing chlorobenzene (130° C.). Another known technique for reducing occluded free bromine content is to grind, mill, or otherwise pulverize the product so that trapped bromine can be liberated and removed by solvent washing. Commercially, a high-melting flame retardant such as decabromodiphenylethane, is heated at high temperatures (280-300° C.) in order to reduce substantially the amount of free bromine trapped inside the particles as formed. In fact, free bromine is so tightly bound to the particles of decabromodiphenylethane that an extended period of time is typically required in order for the free bromine content to be reduced to the desired specification of less than 300 ppm (wt/wt). This high-temperature treatment of the crude decabromodiphenylethane product, coupled with an associated drying step, tends to add significantly to the overall cost of manufacturing this product and also leads to degradation in color.